Hairpin



Patented Feb. 26, 1924. l

UNITED STATES JOSEPH J. OBRIEN, OF SPRINGFIELD, MASSACHUSETTS.

namrm.

Application filed November 9, 1922. Serial No. 599,916.

To all whom it may concern:

Be it known that JOSEPH J. OBRinN, citizen of the United States of America, residing at Springfield, in the county of Hampden and State of Massachusetts, has invented certain new and useful Improve ments in Hairpins, of which the following is a specification.

This invention relates to improvements in hair pins and the leading object of the invention is to provide a self-locking hair pin consisting of a single strand of wire bent upon itself to provide opposing legs and flexible connecting joint of substantially U- shaped formation, each of the legs having cam surfaces formed therein and the whole hair pin being so designed that upon insertion in the hair the cam surfaces will, upon engaging in the hair bring the terminal points of the legs together so as to lock the strand of hair that has been wedged between the legs of the hair pin, the entire hair pin being constructed without requiring any additional material over a standard hair pin of U-shaped construction.

Other objects of the invention will appear in the description annexed hereto which is fully illustrated in the following draw ings; in which:

Fig. 1 is a plan view of one form of the invention.

Fig. 2 is an edge view thereof.

Fig. 3 is a transverse sectional view'taken on line 3, looking in the direction of the arrow.

Fig. 4 is a plan view showing the jaws of the hair pin in locked position.

Fig. 5 is a plan view of a modified form.

Fig. 6 isa similar view of another modified form.

Fig. 7 is a'plan view of still another modified form.

Fig. 8 is an edge view thereof.

Fig. 9 is a plan View of a fourth modified form.

Fig. 10 is an edge view thereof.

The standard hair pin is constructed with legs which diverge from the joint connecting the legs to each other and in some cases these legs are corrugated so that the corrugations form internally facing bends in registration with each other, the bends of the legs of the hair pins merely serving to provide recesses into which the hair may fit and to ofier greater resistance to the withdrawal of the hair pin. When this hair pin is inserted in the hair the legs are spread apart and the hair forced between the corrugated portions of the legs and gripping action depends upon the resiliency or-r'esi'stance offered by the joint of the hair pin to the pressure developed by the hair between the legs of the hair pin.

In my invention the action obtained. with the ordinary hair pin is reversed, in, that after initial insertion in the hair, theterminal portions or jaws of the legs of the hair pin are brought together by a wedging action developed by cam surfaces formed on the edge of the hair pin and the hair itself so that the hair is retained in a closed space formed between the legs of the hair in Figs. 1 to 4;, ahair pin is shown c'onsisting of a single piece of wire A which is bent upon itself to provide opposing legs A and A and an integral connecting U- shaped joint A The leg A is provided with an outwardly curved portion or cam A and the leg A is provided with asimilar outwardly curved cam forming portion A the two portions A and A being disposed in registration with each other and being located near the joint A and the terminal portion or jaws A and A of the hair pin. The leg A is preferably formed with a corrugation A located between the cam A and the joint A and this corrugation A extends at right angles to the plane of the corrugation or cam A. The leg A is provided with a similar corrugation A which extends in an opposite direction to the cam A but at right angles to the plane of the cam A. Each of the cam forming portions A and A extends outwardly of the terminal portion'of its leg so that the maximum diameter of the hair pin at'the greatest width between the cams A and A is prefer ably in excess of the maximum diameter of thehair pin at any other point taken across the legs A and A WVhen the jaws A and A are forced into the hair so as to bring the cam portions A and A, into contacting engagement with and A and A and A will assume the position indicated in Fig. 4, thus providing a closed hair pin with the hair located between the legs of the hair pin against accidental withdrawal. The space between the cams A and A provides a pocket to receive the hair wedged between the legs of the hair pin and this tends to assist in locking the hair pin against endwise movement in the hair.

In Fig. 5'1 show a slightly modified form of the invention with corrugations B and B formed on the legs of the hair pin B. The legs of the hair pin are provided with cam surfaces B and B".

The outwardly disposed cam forming nortions A and A constitute the meeting points of difierently inclined 0r sloping portions of the legs A and A These cams are located nearer the bend A than the opposite or open end of the hair pin, so that the two legs will function as levers, upon the bend as a common fulcrum, and the small movement produced by the action of the hair upon the cams will produce a greater movement of the leg terminals toward each other. The forward side of each cam slopes toward the axis of the open end or throat of the hair pin at a smaller angle than the rearmost side of said cam, which is disposed on a sharper angle so that resistance to withdrawal will be greater than resistance to sertion of the hair pin in the hair.

The portions of the legs from the tips of the cams to their terminals thus form grades or inclined planes which distribute the load of insertion over a greater length and surface, while the rearmost sides of the cams form inclined planes or grades which offer greater frictional resistance to the withdrawal of the hair pin, since the pressure per unit of length is greater on the shorter sides of the hair pin cams, owing to their sharper angles, than on the longer sides thereof.

In Fig. 6 I show another modified form of the invention whereby the corrugations A and A are omitted and the cam surfaces C and C are provided on the legs of the hair pin C.

In Figs. 7 and 8 I show another modified form of the invention whereby a hair pin D is provided with legs D and D with cam surfaces D and 13* formed therein. The terminal portion of the legs D is provided with a corrugation D and the terminal portion of the leg D is provided with a similar corrugation D but extending in opposite directions, both the cams D and 1) being disposed on planes at right angles to the cams D and D. The corrugations of the legs of the hair pin B are disposed in parellel lines so that they will have an interfitting action when the jaws are brought together.

In the case of the corrugations of the hair pin A, identified by the reference letters A and A", and the corrugations of the hair pin D identified by the reference letters I) and I) no resistance is developed by the pressure of the hair opposing the action of the cams of the hair pin, such cams serving to lock the hair pin in its elected position in the hair and to not interfere with nor modify the movement of the legs toward each other.

In order to provide for increased fiexi bility of the joint connecting the two legs of the hair pin, the joint portion of the hair pin may be corrugated in a plane at right angles to the axis of the hair pin as indicated in Fig. 3. In this case the corrugated end of the hair pin provides a slightly wider surface so thatit would be easier for the finger of the user to insert the hair pin in the hair.

In Figs. 9 and 10 I show a fourth modified form wherein the U-shaped hair pin E is provided with legs E and E, each having an outset cam forming portion E located midway of the ends of the hair pin. Each cam forming portion or bend in each leg has a forwardly inclined portion E and a rearwardly inclined portion E, the former inclined portion E being disposed at a smaller angle to the axis of the hair pin than the inclined portion E so that less resistance will be ofi'ered by the cams to the insertion of the hair pin and to the withdrawal of the hair pin. The opposing portions of the legs E and E between the cams E and the bend E are shown to be parallel but they may converge toward each other or diverge from each other. The portions of the legs which extend endwise of the cams E are shown to have corrugations E which are disposed at right angles to the direction of the cams E so that the distance between the legs is not reduced or varied by said corrugations or the cams do not neutralize nor modify the closing and opening action of the cams. The cams are disposed slightly inwardly of the terminals of the legs, thus locking substantially parallel terminal portions of the hair pin. This construction permits of the manufacture of hair pins which differ but slightly from the standard hair pin but which embodies the self closing motion.

Having described my invention I claim:

1. A hair pin consisting of a U-shaped bodyproviding opposing legs spaced apart from each other, the legs being provided with terminal portions forming hair entering points, said terminals being spaced apart from each other a less distance than the portions of the legs near the longitudinal center thereof, and said portions being disposed outwardly of the planes of the terminals to provide leg propelling cam surfaces, the

said outwardly disposed portions having sloping surfaces and being capable of moving the terminals into contiguous relation when the hair pin is inserted in the hair, but not into cross-wise relation.

2. A hair pin consisting of a U-shaped body providing opposing legs relatively movable toward each other and a connecting bend portion, a portion of each leg between the bend and its terminal being disposed outwardly of the plane of the terminal portion to form a cam surface on its outer side and a hair pocket on its inner side, said portions having a width greater than the maXimum width of the hair pin at any other point thereon, said cam surfaces being oflset to a depth and located from the bend and the leg terminals a distance sufficient to produce a self closing movement on the terminal portions of the leg to bring them into contiguous but not crossing relation.

8. A hair pin consisting of a U-shaped member providing a pair of relatively yieldable legs and a connecting bend, each leg having an outset portion, the outset portion of one leg being in the same general plane as the outset portion of the other leg and each leg converging toward the other leg from its outset portion to the terminal of said other leg, the terminal portions of the legs being spaced apart a less distance than the greatest distance between the outset portions, the legs converging toward the bend from said outset portions and each leg having a corrugated portion.

4. A hair pin consisting of a single piece of wire shaped to provide opposing sides and a connecting U-shaped bend, each of the sides being formed with an outward bend presenting gradually sloping surfaces, the terminals of the sides being spaced apart from each other to admit hair therebetween on the insertion of the hair pin in the hair, the said terminals being spaced inwardly of the planes of the outward bends and the outward bends having outwardly disposed arches of depths sufficient to move the terminals of the sides into contiguous but not crossed relation when the hair pin is inserted in the hair upon the engagement of said arches by the hair, said arches being spaced inwardly of the U-shaped bend and the dis tance between the sides of said U-shaped bend being substantially equal to the minimum distance between the sides forwardly of said arches.

5. A hair pin formed of flexible material and bent upon itself to provide opposing legs relatively yieldable, each leg having an outwardly disposed cam forming surface located between its terminal and the bend of the hair pin, the forward side of each cam being disposed. on a lesser incline than the rearmost side thereof, the inclination of the rearmost side of each cam being the reverse of the foremost side, whereby the resistance to insertion of the hair pin will be less than the resistance offered to withdrawal when the hair pin is disposed in human hair, the cam forming surfaces being offset a distance suflicient to move the terminals of the hair pin legs into contiguous but not passing relation, the terminals of the legs being disposed inwardly of the planes of the outermost portions of the cam forming surfaces, the sides of the hair pin converging forwardly and rearwardly of said cam forming surfaces and said surfaces being located nearer the bend of said hair pin than the terminals of the legs.

Signed by me at Springfield, Mass.

JOSEPH J. OBRIEN. 

